In recent years, with the popularization of electronic products such as mobile phones with a fingerprint-identification-unlocking function, fingerprint identification technology has been pushed into a new application era. The process of fingerprint identification in an electronic product is usually controlled by a fingerprint identification circuit.
FIG. 1 shows a structural diagram of a fingerprint identification circuit in the prior art, as shown in FIG. 1, the fingerprint identification circuit usually comprises a plurality of sensing electrodes 10 arranged in rows and columns, a plurality of scanning lines G (for example G1, G2, G3 and G4 in FIG. 1), a plurality of detection signal writing lines X (for example, X1, X2, X3 and X4 in FIG. 1) and a plurality of TFT switches 11 corresponding to the sensing electrodes 10.
Operation process of a first row of sensing electrodes in the fingerprint identification circuit shown in FIG. 1 will be described in detail below, and the operation process specifically includes the following stages.
(a) a detection signal writing stage: applying a driving voltage to the scanning line G1, so that the first row of TFT switches 11 are turned on, at the same time, writing a detection signal to each of the sensing electrodes 10 in the first row through the detection signal writing lines X1-X4 respectively.
(b) a fingerprint sensing stage: when no fingerprint texture sensing occurs, on a basis of capacitances generated by the sensing electrodes 10, each of the sensing electrodes 10 in the first row has a same potential, as shown by D1-D4 in FIG. 2a; when the sensing electrodes 10 are touched by a finger, since the fingerprint texture includes two morphologies consisting of peaks and valleys and a distance between a peak and the sensing electrode 10 is different from that between a valley and the sensing electrode 10, therefore, the influence of the peak on the capacitance of the sensing electrode 10 corresponding thereto is different from that of the valley on the capacitance of the sensing electrode 10 corresponding thereto, that is, the peak and the valley have different influence on the potential of the sensing electrode 10 corresponding thereto respectively, and when the fingerprint texture sensing occurs, potentials of the sensing electrodes 10 in the first row become different, as shown in FIG. 2b. 
(c) a signal reading stage: each of the detection signal writing lines X is connected to a reading sub-circuit 12, as shown in FIG. 2c, the reading sub-circuit 12 is configured to read a sensing signal generated in the sensing electrode 10 after the fingerprint texture is sensed and process the sensing signal.
(d) a comparison process stage: comparing the detection signal written in the step (a) with the sensing signal read in the step (e), and determining whether the fingerprint texture corresponding to a position where each of the sensing electrodes 10 is located is a peak or a valley based on the difference obtained by the comparison.
And so forth, the above (a)˜(d) are repeated, a second row of sensing electrodes, a third row of sensing electrodes, till to the last row of sensing electrodes are scanned in turn, so as to determine whether the fingerprint texture corresponding to a position where each of the sensing electrodes 10 of the overall fingerprint identification circuit is located is a peak or a valley.
However, the existing fingerprint identification circuit has the following problems in practical applications: the fingerprint identification is time-consuming and low accuracy.